Effect of Hexazinone Rate and Formulation on Loblolly Pine in Broadcast Release Applications

1991 ◽  
Vol 15 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Glenn R. Glover ◽  
Bruce R. Zutter ◽  
Patrick J. Minogue ◽  
Dean H. Gjerstad
Keyword(s):  
Loblolly Pine ◽  
Growth Response ◽  
Foliar Spray ◽  
Basal Area ◽  
Soil Characteristics ◽  
Liquid Formulation ◽  
Maximum Volume ◽  
Sand Surface ◽  
Volume Production ◽  
Pellet Formulation

Abstract Growth response and mortality of loblolly pine were examined 5 or 6 years after broadcast applications of four rates of pellet and liquid (applied as a foliar spray) hexazinone formulations for pine release at seven locations across the South varying in soil characteristics. Adjusted hardwood rootstock density 2 years following treatment was significantly affected by treatment and rate at all locations, and by formulation at five of the seven locations. Pine mortality was positively related to hexazinone rate at four of the study locations. Mortality was significantly higher for the pellet formulation compared to the liquid at the two locations with loamy sand surface soils. Mortality averaged less than 10% for the prescribed rate of both formulations at five of the seven locations, and at a sixth location for the pellet formulation. Mean pine height and dbh responses across hexazinone rates were greater than no treatment (check) at three and five locations, respectively. Response in dbh was positively related to hexazinone rate at three locations, and inversely related to rootstock density 2 years after treatment at six of seven locations. Mean treatment response for pine basal area and total volume (outside bark) per acre were significantly greater than the check at only two locations due to high pine mortality at some locations for 1.4X and 2.0X the prescribed rate. Mean increases in volume of the prescribed rate over the check were 9 and 7% for the pellet and liquid formulations, respectively. Maximum volume production increases across locations were 13% for the pellet formulation and 15% for the liquid formulation. South J. Appl. For. 15(1):54-61.

scholarly journals Ertragskundliche Aspekte und Strukturdynamik der Buchen-Lichtwuchsdurchforstung

2018 ◽  
Vol 169 (6) ◽  
pp. 332-339 ◽  
Author(s):  
Joachim Klädtke
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Structural Diversity ◽  
Maximum Volume ◽  
Negative Effects ◽  
Single Tree ◽  
Stand Productivity ◽  
Single Tree Selection ◽  
Volume Production ◽  
Equilibrium Growth

Effects of heavy selective thinnings in beech stands with regard to stand productivity and structural diversity Based on thinning trials in beech stands initiated in the early 1970s, the effects of selective thinnings in favour of 100 to 120 future crop trees were analysed with regard to volume productivity and the stands' structural diversity. The results show that these kinds of thinnings reduce volume productivity by approximately 6% compared to the maximum volume growth. The reduction in volume growth is mostly caused by the fact that the strongly released crop trees have reduced their height growth for the benefit of a lateral crown expansion, while basal area growth was not affected. Calculations indicate that silvicultural systems working with only 50 future crop trees per hectare may decrease the maximum volume production by about 12%. Furthermore, the results show that the intense crown releases caused by selection thinnings increase the horizontal and vertical diversity of beech stands, since the trees in the understorey profit from better light conditions. The indices calculated for diameter and height diversity of the selection thinning plots approach the values being typical for single tree selection forests (“Plenterwälder”). Already after three to four consecutive selection thinnings, the beech stands' diameter distributions displayed an exponentionally decreasing shape typical for single tree selection forests close to equilibrium. Growth simulations revealed that it might even be possible to directly transform beech stands by selection thinnings into single tree selection structures. However, presumably negative effects on timber quality to be expected under single tree selection structures should be considered as a critical aspect with regard to theoretically possible transformation.

Effects of diameter distribution on the growth of simulated uneven-aged sugar maple stands

1987 ◽  
Vol 17 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Gerald D. Hansen ◽  
Ralph D. Nyland
Keyword(s):  
Sugar Maple ◽  
Basal Area ◽  
Tree Size ◽  
Diameter Distribution ◽  
Computer Simulation Model ◽  
Maximum Volume ◽  
Size Classes ◽  
Management Objectives ◽  
Stress Maximum ◽  
Volume Production

Effects of diameter distribution on the growth of simulated uneven-aged sugar maple (Acersaccharum Marsh.) stands are described using output from a computer simulation model. Results indicate that the combination of q ratio (a constant ratio between the numbers of trees present in adjacent diameters over the entire range of size classes present), maximum tree size, and basal area should vary depending on management objectives and cutting cycle length. A ratio of 1.2 appears best for describing a diameter distribution to maximize growth of large sawtimber, but larger q ratios are needed in the sapling and pole size classes to insure sufficient numbers of trees to sustain the distribution through the end of a cutting cycle. Retaining trees larger than a 40 cm diameter at breast height offers no advantage when objectives stress maximum volume production. A 50 cm maximum tree size appears better suited for maximizing large sawtimber volume and value growth, but a 40 cm maximum will yield a better compound rate of return on initial stand value. Under all options, longer cutting cycles require lower initial basal area levels.

scholarly journals Long-Term Effects of Drainage, Bedding, and Fertilization on Growth of Loblolly Pine (Pinus taeda L.) in the Coastal Plain of Virginia

2005 ◽  
Vol 29 (4) ◽  
pp. 205-214 ◽  
Author(s):  
Thomas R. Fox ◽  
Kevin H. Kyle ◽  
Lisa J. Andrews ◽  
W. Michael Aust ◽  
James A. Burger ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Coastal Plain ◽  
Growth Response ◽  
Block Design ◽  
Basal Area ◽  
Stand Density ◽  
Site Preparation ◽  
The Other ◽  
Long Term Effects ◽  
Lime Treatment

Abstract A site preparation study was established in 1968 at three locations in the Coastal Plain of Virginia. Three treatments were installed in a randomized complete block design: (1) chop, (2) bed, and (3) ditch. In 1978, four fertilizer treatments were superimposed on the site preparation study: (1) check, (2) phosphorus (P) only, (3) P + nitrogen (N), and (4) P + N + lime, converting it into a split-plot design. At age 33 years, height of the dominant loblolly pine in the ditch treatment was significantly greater than in the other site preparation treatments. However, there were no differences in stand density, diameter at breast height (dbh), basal area, or volume because of site preparation. This contrasts with the data collected at age 21 years, when total volume in both the bed treatment and the ditch treatment was greater than in the chop treatment. Changes in water table depths through time were the probable cause for decreased response to bedding and ditching. There was a large response to fertilization through age 33 years in this study. The P + N + lime treatment had significantly greater dbh, basal area, and volume than the other fertilizer treatments, which significantly increased pine stumpage value. The size of the growth response was greater at age 33 years than it was at age 21 years. Soil and foliage analysis suggests that the sustained growth response at this site was due to the added Ca. South. J. Appl. For. 29(4):205–214.

Ten-Year Growth Response of a California Red and White Fir Sawtimber Stand to Several Thinning Intensities

1988 ◽  
Vol 3 (2) ◽  
pp. 41-43 ◽  
Author(s):  
William W. Oliver
Keyword(s):  
Rapid Growth ◽  
Growth Response ◽  
Basal Area ◽  
Growth Potential ◽  
Normal Density ◽  
Abies Magnifica ◽  
Commercial Thinning ◽  
White Fir ◽  
Volume Production ◽  
Stand Basal Area

Abstract A 100-year-old stand of California red fir (Abies magnifica) and California white fir (Abies concolor) of near normal density was commercially thinned from below to 6 basal area stand densities. Growth was analyzed after 10 years. Periodic annual increments (PAI) of diameter, height, total volume, and gross basal area were correlated with reserve stand basal area, but merchantable volume and net basal area were not. Mortality resulted in considerable variation in net PAI. As much as 50% of the stand basal area was removed with negligible loss in total net volume production. When economically feasible, commercial thinning in similar stands can leave a vigorous reserve with rapid growth potential. West. J. Appl. For. 3(2):41-43, April 1988.

Growth response of loblolly pine, sweetgum, and water oak in a pine-hardwood density study

1999 ◽  
Vol 29 (7) ◽  
pp. 968-978 ◽  
Author(s):  
Glenn Glover ◽  
Harold Quicke
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Growth Response ◽  
Basal Area ◽  
Volume Index ◽  
Vegetation Control ◽  
Quercus Nigra ◽  
Pinus Taeda L ◽  
Water Oak ◽  
Density Study

A study was established with loblolly pine (Pinus taeda L.) planted at 1683 trees/ha competing with sweetgum (Liquidambar styraciflua L.), water oak (Quercus nigra L.), or loblolly pine at densities of 0, 1794, 2692, and 5382 trees/ha. The study is a split-split plot with three blocks. Main plots are the three competitor species; subplots are with or without 2 years of herbaceous vegetation control (HVC); and sub-subplots are competitor densities. The study was measured at 6 years after establishment. Pines in pure plots responded to HVC with a mean basal area gain of 1.8 m2/ha (13%). With HVC, basal area increased 2.7 m2/ha (70%) for sweetgum and 2.3 m2/ha (58%) for water oak. Pines in mixed plots did not respond, or responded negatively, to HVC. Pine height, basal area, volume index, and canopy projection were only slightly affected by sweetgum density above zero. Pine characteristics decreased as water oak density increased. Adding sweetgum or water oak to pine reduced total (pine + hardwood) volume index and basal area.

scholarly journals A Dynamic Stand Growth Model System for Loblolly Pine Responding to Mid-Rotation Treatments

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 556
Author(s):  
Mauricio Zapata-Cuartas ◽  
Bronson P. Bullock ◽  
Cristian R. Montes ◽  
Michael B. Kane
Keyword(s):  
Growth Model ◽  
Loblolly Pine ◽  
Basal Area ◽  
Model System ◽  
Growth And Yield ◽  
Site Quality ◽  
Response To Treatment ◽  
Plantation Management ◽  
Vegetation Control ◽  
Dominant Height

Intensive loblolly pine (Pinus taeda L.) plantation management in the southeastern United States includes mid-rotation silvicultural practices (MRSP) like thinning, fertilization, competitive vegetation control, and their combinations. Consistent and well-designed long-term studies considering interactions of MRSP are required to produce accurate projections and evaluate management decisions. Here we use longitudinal data from the regional Mid-Rotation Treatment study established by the Plantation Management Research Cooperative (PMRC) at the University of Georgia across the southeast U.S. to fit and validate a new dynamic model system rooted in theoretical and biological principles. A Weibull pdf was used as a modifier function coupled with the basal area growth model. The growth model system and error projection functions were estimated simultaneously. The new formulation results in a compatible and consistent growth and yield system and provides temporal responses to treatment. The results indicated that the model projections reproduce the observed behavior of stand characteristics. The model has high predictive accuracy (the cross-validation variance explained was 96.2%, 99.7%, and 98.6%; and the prediction root mean square distance was 0.704 m, 19.1 trees ha−1, and 1.03 m2ha−1 for dominant height (DH), trees per hectare (N), and basal area (BA), respectively), and can be used to project the current stand attributes following combinations of MRSP and with different thinning intensities. Simulations across southern physiographic regions allow us to conclude that the most overall ranking of MRSP after thinning is fertilization + competitive vegetation control (Fert + CVC) > fertilization only (Fert) > competitive vegetation control only (CVC), and Fert + CVC show less than additive effect. Because of the model structure, the response to treatment changes with location, age of application, and dominant height growth as indicators of site quality. Therefore, the proposed model adequately represents regional growth conditions.

scholarly journals Competition Effects on Growth and Crown Dimensions of Shortleaf and Loblolly Pine in Mature, Natural-Origin, Pine–Hardwood Mixtures of the Upper West Gulf Coastal Plain of Arkansas, USA: A Neighborhood Analysis

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 935
Author(s):  
Mohammad Bataineh ◽  
Ethan Childs
Keyword(s):  
Loblolly Pine ◽  
Species Abundance ◽  
Basal Area ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Species Identity ◽  
Linear Mixed Effects ◽  
Natural Origin ◽  
Pinus Taeda L ◽  
Crown Dimensions

The need for a comprehensive and mechanistic understanding of competition has never been more important as plants adapt to a changing environment and as forest management evolves to focus on maintaining and enhancing complexity. With the recent decline in shortleaf pine (Pinus echinata Mill.) land area, it is critical to determine the effects of competition on shortleaf pine and its performance against loblolly pine (Pinus taeda L.), the preferred planted replacement. We evaluate differences in shortleaf and loblolly pine 10 year mean basal area increment (BAI) and crown dimensions across a gradient of neighborhoods. Linear mixed-effects regression models were developed using BAI and several crown metrics as responses and crowding, competitor species abundance and identity, and initial size and species identity of focal tree as predictors. Crowding of focal trees negatively impacted BAI and crown size (p < 0.001, respectively). Although loblolly pine had three times higher BAI as compared to shortleaf pine within similar neighborhoods, BAI was variable, and the crowding effect did not differ between shortleaf and loblolly pine (p ranged from 0.51–0.99). Competitive impacts on focal trees did not differ by competitor identity (p ranged from 0.07–0.70). Distance-independent competition indices better explained the variation in BAI and horizontal crown metrics, while distance-dependent size ratios were more effective at evaluating vertical crown metrics. These findings highlight shortleaf pine competitive potential in mature, natural-origin stands and provide support for the restoration of pine–hardwood and hardwood–pine stratified mixtures as well as management of shortleaf pine at long rotations.

scholarly journals Response of Loblolly Pine Plantations to Late-Rotation Fertilization and Herbicide Applications in North Louisiana

2000 ◽  
Vol 24 (3) ◽  
pp. 166-175 ◽  
Author(s):  
Roger A. Williams ◽  
Kenneth W. Farrish
Keyword(s):  
Old Age ◽  
Loblolly Pine ◽  
Growth Response ◽  
Block Design ◽  
Volume Growth ◽  
Pine Plantations ◽  
Discount Rates ◽  
Rates Of Return ◽  
Age Class ◽  
North Louisiana

Abstract Late-rotation fertilization was studied over a 6 yr period in loblolly pine (Pinus taeda L.) plantations in north Louisiana. Fertilizer (150 lb/ac of nitrogen and 50 lb/ac of phosphorus) and herbicide (hexazinone, 2.5 lb ai/ac) were applied to five loblolly pine plantations in the 25-yr-old age class (25-26 yr), and five plantations in the 30-yr-old age class (30-32 yr). The study was established as a randomized block design with three blocks in each plantation. Three treatments studied were fertilizer (F), fertilizer+herbicide (FH), and herbicide (H), which were compared to a control. Diameter and volume growth responded significantly to treatments F and FH in both age classes. A greater per-tree response occurred in the 25-yr-old age class as a result of the additive effect of recent thinnings. The use of herbicide in treatments FH and H did not cause a significant increase in growth response. The growth response in treatment FH was not significantly different from the response in treatment F, nor was the growth response in treatment H significantly different from the control. In the 25-yr-old age class the response to fertilization (treatments F and FH) was allocated primarily to the larger trees. Treatments F and FH increased total volume growth (lb) by 48 and 55 ft3/ac/yr, respectively, over control plots while treatment H increased growth by 15 ft3/ac/yr. In the 30-yr-old age class, the response was distributed more evenly among all diameter classes. Treatments F and FH increased total volume growth on average of 58 and 60 ft³/ac/yr, respectively, over control plots while treatment H increased growth by 17 ft3/ac/yr. An economic analysis was performed using discount rates of 8% and 12%, and current prices and costs at the time of the study. Rates of return ranged from 29.6 to 38.8% under various economic scenarios (discount rates, prices and costs) in the 25-yr-old age class. The net present value equivalent to an annual income (EAI) gain for each of the 6 yr of the study ranged from $34.07-$60.54/ac/yr. These same economic scenarios produced rates of return of 23.3 to 31.9% in the 30-yr-old age class, with an EAI range of $18.98-$40.03/ac/yr. South. J. Appl. For. 24(3):166-175.

scholarly journals Growth After Thinning a 35-Year-Old Natural Stand to Different Loblolly Pine and Hardwood Basal Areas

1997 ◽  
Vol 21 (4) ◽  
pp. 168-174
Author(s):  
Michael G. Shelton ◽  
Paul A. Murphy
Keyword(s):  
Loblolly Pine ◽  
Block Design ◽  
Volume Growth ◽  
Basal Area ◽  
Timber Production ◽  
Product Class ◽  
Randomized Complete Block Design ◽  
Timber Products ◽  
Total Growth ◽  
Area And Volume

Abstract Growth was monitored for 4 yr in a thinned stand in southern Arkansas with three pine basal areas (70, 85, and 100 ft2/ac) and three hardwood basal areas (0, 15, and 30 ft2/ac); pretreatment basal areas averaged 119 and 33 ft2/ac for pines and hardwoods, respectively. Treatments were arranged in a 3 X 3 factorial randomized complete block design with three replicates, yielding 27 permanent 0.20 ac plots. Growth variables were regressed with residual pine and hardwood basal areas. Pine basal area and volume growth increased with the pine stocking level after thinning and decreased with the level of retained hardwoods. For basal area and merchantable volume, hardwood growth largely compensated for losses in the pine component, and thus, hardwood retention had little net effect on the total growth of the stand. The greatest impact of hardwood retention was on the stand's sawtimber growth, because hardwoods did not contribute to this product class. Each 1 ft2/ac of retained hardwood basal area reduced pine sawtimber growth by 6 to 10 bd ft Doyle/ac/yr, depending on the pine stocking. Because large differences existed in the value of timber products, retaining 15 and 30 ft2/ac of hardwoods reduced the value of timber production by 13 and 24%, respectively, at 4 yr after thinning. South. J. Appl. For. 21(4):168-174.

Sign in / Sign up

Export Citation Format

Share Document